Cell differentiation is an important process in multicellular organisms. Describe what cell differentiation is and explain why, once a cell has differentiated, it cannot produce a cell with a different specialised function.

Cell differentiation is the process by which a cell becomes specialised to perform a particular function, increasing the efficiency of a multicellular organism.

During differentiation the cell alters the expression of genes in its DNA, so that only a specific set of proteins are produced.

Once a cell has differentiated it cannot revert to an unspecialised state because it has lost the ability to express the genes required for other functions.

If a differentiated cell divides, the daughter cells inherit the same specialised gene expression pattern and therefore perform the same function.

Thus a differentiated cell cannot produce a cell with a different specialised function – for example, a heart cell cannot divide to produce a skin cell.